RAPID: Hurricane Harvey Rapid Response: In-Situ Barrier Island Storm Impact and Recovery Measurements of Hydrodynamics, Morphodynamics, and Sedimentation Acr. Hog and F. Island TX

由于部署的提前通知时间短、仪器故障或丢失的可能性以及特定地点实际风暴影响的不确定性，很难获得极端风暴对沿海系统影响的快速响应现场测量结果。该项目提高了测量受极端事件影响的屏障岛屿系统表面的详细水动力过程（水流和波浪）的能力。这些数据将提供前所未有的信息，以增强风暴影响的地面实况预测建模能力。对两个选定现场（豪格岛和福莱特岛）的即时和中期（数周至数月）恢复情况的详细分析将进一步阐明障壁岛系统的风暴后恢复动态，这对于了解相对海平面上升和更频繁和/或更强烈热带风暴的可能性至关重要。研究团队在2017年8月25日飓风哈维登陆前三天，沿着德克萨斯湾中部和上部海岸线部署了一组五个“快速反应单元”（RRU），以增强沿海社区的抵御能力。RRU站点在登陆点和加尔维斯顿之间大约一半的两个位置提供详细的测量结果，并对风暴对这两个系统的影响进行详细的比较研究。RRU包含记录水位波动和波高的压力传感器，测量海流和轨道波速的倾斜海流计，声学多普勒测速仪和GoPro延时成像系统。这些数据将在使用无人机系统和标准摄影测量处理算法生成的风暴前和风暴后数字高程模型（DEM）的背景下进行解释。风暴后的快速反应活动还包括陆上和涉水深度真实的时间动态（RTK）海滩剖面断面和表层沉积物取样以及对冲刷沉积物取芯。最初的每周无人机飞行计划，随后是每月调查，将记录飓风后屏障系统的恢复情况。

Rapid response field measurements of extreme storm impacts to coastal systems are difficult to obtain due to short advance notice times for deployment, potential for instrument failure or loss, and uncertainty in actual storm impact for specific locations. This project advances capabilities to measure detailed hydrodynamic processes (currents and waves) across the surface of barrier island systems impacted by extreme events. The data will provide unprecedented information to enhance and ground-truth predictive modeling capabilities of storm impacts. Detailed analysis of immediate and medium term (weeks to months) recovery of the two selected field sites (Hog and Folletts Islands) will shed further light on post-storm recovery dynamics of barrier island systems that are critical to understand in the context of relative sea level rise and the potential for more frequent and/or intense tropical storms. In turn, this knowledge can help bolster the resiliency of coastal communities.The research team was able to deploy a set of five "Rapid Response Units" (RRUs) along the central and upper Texas Gulf coastline three days prior to Hurricane Harvey's landfall as a Category 4 storm on August 25, 2017. The RRU sites provide detailed measurements at two locations roughly half way between the landfall point and Galveston, and enable detailed comparative studies of the storm's impacts on these two systems. The RRUs contain pressure transducers to record water level fluctuations and wave heights, tilt current meters to measure current and orbital wave velocities, acoustic Doppler velocimeters, and GoPro time-lapse imaging systems. These data will be interpreted in the context of pre- and post-storm digital elevation models (DEMs) generated using an unmanned aerial system (UAS) and standard photogrammetric processing algorithms. Post-storm rapid response activities also include subaerial and wading-depth real time kinematic (RTK) beach profile transects and surface sediment sampling and coring of washover deposits. An initial program of weekly UAS flights, followed later by monthly surveys, would document recovery of the barrier system following the hurricane.